Constant current transformer actuated control system



I. E. M CABE Oct. 4, 1932.

CONSTANT CURRENT TRANSFORMER ACTUATED CONTROL SYSTEM Filed April 23, 1930 '7 Sheets-Sheet 1 R cm:

mart.

INVENTO RA E. M

NORM/3L. IDLE POSITION TORNEY l. E. M CABE Oct. 4, 1932.

CONSTANT CURRENT TRANSFORMER AGTUATED CONTROL SYSTEM Filed April 25, 1950 7 Sheets-Sheet 2 INVENTOR RA E. CABE t/2 flu.

TORNEY I. E. M CABE Oct. 4, 1932.

CONSTANT CURRENT TRANSFORMER-ACTUATED CONTROL SYSTEM 7 Sheets-Sheet 3 Filed April 23. 1950 INVENTOR RA ELIJl cAbE BY I h TTORNEY.

.N mm m MW Q M s om NN Oct. 4, 1932. E. M CABE 1,381,321

CONSTANT CURRENT TRANSFORMER ACTUATED CONTROL SYSTEM Filed April 23, 1930 7 Sheets-Sheet 4 5. POSITION UPON INITIAL. FAILURE. OF IGNLTION ."IINVENTO R IRA E1. PA CABE'.

TTORN EY Oct. 4,1932. l. E. M CABE 1,831,321

CONSTANT CURRENT TRANSFORMER ACTUATED CONTROL SYSTEM Filed April25, 1930 'r Sheets-Sheet 5' POSITION UPON CURREN T INTERRUPTION WFFH MOTOR SWITCH CLOSED BUT STACK SWJTCH OPEN INVENTOR ERA K. {W CABE ATTORNEY Oct. 4, 1932. I MCCABE 1,881,321

CURRENT TRANSFORMER ACTUATED CONTROL SYSTEM CONSTANT 7 Sheets-Sheet 6 Filed April 25, 1930 5 POSVHON UPON CURRENT INTERRUPTION HCK SWITCHES CLO5- WITH MOTOR AND sT G mom SWITCH CLOSED ED AND J N INVENTOR IRA E. QAEE CONTROL SYSTEM 7 Sheets-Sheet 7 Oct. 4, 1932. l. E, M CABE CONSTANT CURRENT TRANSFORMER ACTUATED Filed April 25, 1950 MOMENTARY CURRENT 5 POSFI'ION UPON DURING- NORMHL RUNNING INTERRUPTION Q ss mm BY{O .7 I

- ATTORNEY Patented Oct. 4,1932;

IRA E. MCCABE, OF CHICAGO, ILLINOIS CONSTANT CURRENT TRANSFORMER ACTUATED CONTROL SYSTEM Application filed April 23,

This invention relates to improvements in electrical control devices and more particularly to a constant current transformer actuated control system especially adapted for electrically operated or actuated fluid fuel burner mechanisms.

It is customary to provide fluid fuel burner mechanisms employed for domestic heating purposes with a room thermostat which automatically starts and stops the burner in accordance with the temperature desired in the building and in addition thereto it is desirable to provide control devices which provide electrical means for igniting the fuel when supplied by. the mechanism and'other vmeans'injthe form of safety devices to cause the burner mechanism to shut down in case the fuel fails to ignite upon initial operation of the mechanismor if the flame fails or is extinguished during operation.

It is an object of this invention to provide a control device which provides in a single instrument means actuated by the closing of the room thermostat, or other switch in the circuit of the system, which will first operate the electrical ignition device, then operate the mechanism to supply the fuel and, a suificient time thereafter for the fuel to be ignited, discontinue the operation of the ignition device, also in case of failure to secure ignition of the fuel to shut down the mechanism and require a manual resetting of the control before operation can be resumed, as well as upon failure of the combustion after initiated or upon an interruption of the commercial line current at any time while the room thermostat or switch is closed to shut down the burner mechanism and cause the parts to assume the normal cold position and to recycle or perform the normal starting operation immediately upon the resumption of the current without a manual reset. In the case of such failure of combustion, if the cause has not been removed there will be no initial ignition when the mechanism recycles and there will result a shut down thenrequiring a manual reset. In the event of a current interruption, the time required for the recycling or restarting operation is always, suf- 1930. Serial No. 446,573.

ficient to allow the unburned vapors in the combustion chamber to become dissipated.

It is a further object of this invention to provide a constant current transformer which supplies a current of constant inten- 5;, sity to the ignition device and the control actuating mechanism to then close the circuit to cause the burner mechanism to sup ply fuel. and thereafter automatically open the transformer circuit. "lhe provision of a 5; constant current passing through the ignition circuit makes it possible to interpose therein a suitable electrical resistance element that will always become incandescent after the current has passed thereof:

through for a known time, thatwill not burn out and not be affected by carbon depositedthereon and therefore provide a reliable ignition 'gdevice. Furthermore, the constant current allows the interposition in the ignition circuit of a thermal member for coacting with other parts for causing the burner motor switch to close and the iginition switch to open, such as a strip of bimetallic metal, which will produce a known movement in a known time after the circuit is closed therethrough. The ineluding in the ignition circuit of the thermal member actuated by the passage of the current therethrough to coact with other parts to close the motor switch will prevent the initial supply of fuel to the burner mechanism if the ignition circuit becomes inoperative for any reason, such as the ignition device becoming defective or a broken connection 115 in the ignition circuit, because the thermal elsment willthen remain cold and immova le. i

This invention also contemplates employing the weight and movement of the coil of 80 the constant current transformer that is electrically repelled or caused to float' above the. other coil whenthe transformer is energized to actuate the control in such a manner that p when the burner mechanism is shut down 5 and the transformer deenergized the weight of the moveable coil prevents any operation of the burner mechanism and the floating of the moveable coil when the transformer is energized immediately not only sets up a.

current of constant intensity in the ignition circuit but also releases and. allows other coacting parts to proceed to cause the closing of the circuit to the burner mechanism to supply fuel and thereafter cause the opening of the ignition circuit. This invention further contemplates the provision of means caused to operate upon the establishment of combustion of the fuel and act before the circuit to the transformer is opened to support the weight of the floating coil when deenergized during the normal operation and upon the occurrence of an abnormal condition, such as a flame failure or current interruption, to employ the supported weight of the dead or deenergized coil to cause a shut down of the burner mechanism.

lhe intensity of the commercial current varies in different localities and sometimes varies in the same locality. By connecting the commercial line to the primary coil of a constant current transformer and a hot wire ignition device in the secondary a current .whlch a hot wire 1gn1t1on device 1semof constant intensity passes through the circuit of the ignition device. If the voltage iofthe commercial line is too low to induce a secondary current of suflicient intensity to heat the resistance ignition device to incandescency the primary coil will not float and therefore the control Will not operate. No matter how much the commercial voltage fluctuates within reasonable limits about that required to operate the ignition device, the current passing through that circuit is substantially constant.

This invention contemplates that the circuit through the transformer be normally closed by a switch in the control, and as this switch controls the ignition circuit it will hereinafter be referred to as the ignition switch. It also contemplates that the circuit to the electrically operated or actuated burner mechanism be normally opened by a switch in the control, which will be hereinafter called the motor switch, and the closing of the motor switch may either operate a motor to pump or otherwise supply liquid fuel or a valve to allow the flow of a liquid or gaseous fuel. Therefore, the closing of the room thermostat first closes the line circuit through the transformer, then through both. transformer and motor and then through the motor alone.

Different types of burner mechanisms in ployed require different lengths of time for the heating of the ignition device'before the fuel is supplied and different times after-the fuel is supplied before the ignition device is out out. In an ignition circuit of constant known or determined constant intensity, and

as provided by this invention, the period of pre-heating or pro-ignition may be readily determined and adjusted as required for any particular burner and likewise the period of post-heating or post-ignition.

This invention also contemplates the employment of a holding magnet in the control which in turn is controlled by a switch responsive to the presence or absence of the flame from the ignited fuel so that when ignition occurs the magnet is energized. It is contemplated that the energizing of the magnet cooperates to hold the motor switch in closed position as long as ignition occurs normally and at the same time causes the sup porting of the weight of the floating coil after the ignition switch has opened.

This invention also contemplates the provision and arrangement of parts responsive to both the weight of the dead coil and presence or absence of the fuel flame to cooperate upon a current interruption to cause a shut down of the burner mechanism and to cause a recycling of the control to again go through the movements of a normal start upon re-' Figure 2 is a view in side elevation of the control panel, looking to the right of Figure 1, with the covers shown in section and the thermal strip shown in dot and dash lines.

- Figure 3 is a view similar to Figure 1 illustrating the positions assumed by the respective parts when the burner is normally running, including awiring diagram illustrating the electrical connections to'the various elements of the burner control system.

Figure 4 is a detail view in front elevation illustrating the positions assumed by the respective parts in case of initial ignition failure, omitting the motor and ignition switches.

Fi are and Figure 6 is a similar view in side elevation, 0 the means for adjusting the ignition period.

Figure 7 is a view similar to Figure 4 illustrating the positions assumed by the respective parts in case of a current interruption at a certain time.

Figures 8 and 9 are views similar to Figure 7 when the current interruption occurs at othler times during the actuation of the contro Y igure 10 is adetail view of the thermal strip.

Referring to Figures 1 and 2, this preferred form of this invention comprises a panel '1 5 is a detail View in. front elevation,

III

which the rectangular core 2 is mounted on the rear side of the panel 1, the body ofthe panel is cut out following the outline of the inner edges of the core 2 and the rear of the core 2 is provided with a ,cover 3. The'mechanism on the front of the panel is protected by acover 4 attached to the panel. 4

The secondary coil 5 of the constant current transformer is stationary and rests upon the bottom portion of the rectangular core 2,

a the panel 1 and are adapted to be connected inthe ignition circuit in a manner hereinafter described in detail.

A yoke 9 in the form of a cylinder, or partial cylinder, corresponding in outline to the outline of the primary coil 6 is mounted to reciprocate in the opening in the panel 1 and within the rectangular core 2 and is provided with a plurality of depending legs 10 each 7 having an inturned foot-11 adapted to enter between the coils 5 and 6.

The switch operating and actuating mechanism is mount-ed on a base plate 12 supported upon thepanel 1 spaced apart a sufiicient distance therefrom to allow movement of both the primary coil 6 and yoke 9 therebehind. A front plate 13, shown in Figures 2, 5, and 6, covers part of the moving parts and is therefore omitted from the other views so as to not obscure or confuse the movements illustrated therein. The babe plate 12 pivotally mounts, in a manner hereinafter described. an

' ignition switch 14 and a motor switch 15, both shown in full lines in Figures 1 and 2,- in dot and dash lines in Figures 3 and 5 and omitted from the other. views to avoid confusion with the moving parts therebehind. These switches 14 and 15 are preferably mercury tube switches of the commercial type shown.

Referring to' Figure 3 and the wiring diagram thereon, it is seen that a series of bindmg posts are arranged in line upon a plate 16 spaced apart from the panel 1 below the fixed secondary coil 5. The lead 17 from the commerc al line is connected to the binding post 18 which post is connected by lead 19 to the motor switch 15' and also by lead 20 to binding post 21 which in turn is connected by lead 22- to a room thermostat R and thence through a boiler control C to binding post 23. Binding post 23'is connected by lead 24 to the ignition switch 14 and also by lead 25 to binding post 26 which in turn is connected by lead 27'through a switch responsive to the presence .or absence of the burner flame, such as a stack switch S, to binding post 28. Binding post 28 is connected through the windings of electro-magnet E by lead 29 to -5 binding post 30 which in turn is connected to the return lead 31 to the commercial line. The incoming current passes through lead 17 from the commercial line, binding post 18 and lead 19 to the motor switch 15 and when the switch is closed passes therefrom through lead 32 to binding post 33 and from thence through lead 34 through burner mechanism motor M to binding post 35 which isv connected by lead 36 to the binding post 30 connected to the return lead 31 to the commercial line. If desired, the incoming current at binding post 33 may be caused to branch so that a portion passes through lead 37 to energize an electrically operated fuel valve 0 in the supply to the burner mechanism and then back to the binding post 35 and thence through lead 36, binding post 30 to return lead 31 to the commercial line. The incoming current passing from binding post 18 through lead 20, binding post 21, lead 22, through the room thermostat R and boiler control C, to binding post 23 and from thence by way of lead 24 to the ignition switch 14 passes the'rethrough, when closed, by way of a flexible lead 38 to one terminal 39 of the windings of the primary coil (5, through said windings to the other terminal'40 and from thence through a flexible lead 41 to bind ng post 35 and from there through lead 36 and binding post 30 to return lead 31 of the commercial line. The room thermostat R, the boiler control C, the stack switch S, the electrically operated fuel valve 0 and the burner motor M are all commercial types.

The ignition circuit remains to be traced upon the diagram on Figure 3 and requires reference to Figure 2 as well. Figure 2 shows one terminal of the windings of the stationary secondary coil attached to binding post 7 and the other terminal of the windings attached to binding post 8. Figure 2 also shows the binding post 8 also engaging one leg of a bifurcated thermal member T, illustrated in dot and dash lines, and which is shown in detail in Figure 10 and will be more fully described hereinafter. The other leg of this member T is engaged by the hindingpost 42 insulated from binding post 8. The ignition circuit is completed by way of lead 43 from binding post- 7 through the ignition device WV to binding post 42 and from thence through the legs of the bifurcated thermal member T to binding post 8. Binding posts 7 and 42 are shown only on Figure 2 as they both lie back of binding post 8 on F gure 3. In this case the ignition device W illustrated is of the hot wire type and preferably constructed in accordance with improved form disclosed in this applicants prior copending application Serial No. 426.521, filed February 7, 1930.

o The ignition switch 14 is preferably mounted in clips depending from a right angular extension 44 from the bottom of a carrier plate 45 mounted on a pivot pin 46 carried by the base plate 12 The motor switch is similarly mounted in clips depending from a right angular extension 47 from the top of a carrier plate 48 mounted on a pivot pin 49 carried on the base plate 12. These switches are so arranged that when the burner mechanism is not operating or in the cold position,

a the ignition switch normally assumes a closed position and the motor switch an open position, as shown in Figure 1. When the room thermostat R closes the circuit from the commercial line through the-control and causes the burner mechanism to operate normally, the switches are caused toassume the running position, shown in Figure 3, with the ignition switch 14 open and the motor switch 15 closed. I

In a hot wire ignition system it is necessary to close the. ignition switch first t-o'bring the ignition wire to incandescence before the burner motor operates to supply fuel'so that the ignition device will be operating when the fuel is first supplied and in all ignition systems the ignition device is usually caused to continue operating a predetermined time after the time the burner motor normally initially supplies fuel to insure ignition. In this control, the ignition switch is normally closed when the burneris cold so-that-when the room thermostat closes, the ignition device is immediately energized and then the motor switch is closed to supply fuel and a predetermined time thereafter the ignition,

switch is opened during normal operation of the control. To accomplish this the follow ing constructions and arrangements of parts are contemplated; As seen from the wiring diagram on Figure 3, when the parts are in the cold position, as shown in Figure 1, the incoming current to binding post 18 cannot pass through lead 19 as the motor switch 15 is open, so it follows through lead 20, bindin g post 21, lead 22, through room thermostat R, when closed, boiler control C, binding post 23, lead 24, through normally closed ignition switch 14, lead 38 to terminal 39 of the primary coil 6, passing through the windings to terminal 40, energizing the coil, and through lead 41, binding post 35, lead .36, binding post 30, to the return lead 31 of the commercial line. The energization of the primary coil 6 energizes the secondary coil 5 and the induced current set up in the secondary passes from binding post 7 by way i of lead 43 through the hot wire ignition de-' vice W to binding post 42 and thence through the legs of the bifurcated thermal member T to binding post 8 of the'other terminal of the secondary coil. i

The completion ofthe ignition circuit thus described accomplishes three things; first, in

energizing the primary coil it causes the coil 6 to float abovethe stationary secondary coil 5, the position it assumes in floating above the coil 5 depends upon the intensity of the current of the commercial line and in all cases frees the feet 11 of the yoke 9 allowing an upward movement of the yoke as hereinafter described; second, in passing through the resistance wire of the ignition device \V it heats the wire to incandesccnce and then maintains it incandescent until the circuit is broken; and, third, inpassing through the legs of the bifurcated thermal member T it increases the temperature of the body thereof.

The thermal member T is formed of a strip of bimetallic metal preferably wider at its bifurcated base and tapering thereabove as shown in Figures 2 and 10 and is so constructed and arranged that as the current passes through the legs of the bifurcated portion, the extremities of this portion being each held stationary by binding posts 8 and 42, the body of the member becomes heated and the upper free end is caused to move or bend in the direction of the center of the panel 1.

This movement of the free end of the thermal actuating roller carried on the free end of an actuating lever 50 is adapted to travel, the rollerbeing maintained in contact with one sloping edge or the other of the plate by a spring 51. The other end of the actuating lever 50 is pivotally connected to an actuating member 52 in the form of a plate pivotally mounted on the pin 53 carried upon the base plate 12. Movement of the actuat ing member 52 about its pivot 53 imparts movementto the actuating roller and as it travels over the apex of the nose of the. ignition switch carrier plate 45 it snaps it into the open or closed position, as the case may be, as disclosed in this applicants prior Patent No. 1,734,016, dated October 29th, 1929.

The free end of the thermal member T is pivotally connected to one end of an adjustable actuating link 54, the other end of which is provided with a slot 55 adapted to receive a pin 56 on the actuating member 52 and engage the pin 56 at the ends of the slot as the.

link is moved thereover. A coil spring 57 is connected at one end to the pin 56 and at the other end to the body of the link 54 which normally draws the left end of the slot 55 into engagement with the pin 56. These parts are so arranged and adjusted that when the control is in the cold position, as shown in Figure 1, and the ignition switch 14 is closed the actuating roller engages the upper sloping edge of the carrier plate 45 and is held in engagement therewith by the tension of the spring 51 which also through actuating lever 50 imparts a rotative movement to sage thereof through the legs of the thermal member T causing the free end to bend or move toward the center of 'the panel 1 imparts through actuating link 54 a rotative movement to the right to the pivoted actuating member 52 which in turn imparts a downward movement to the actuating lever 50 caus ing the actuating roller thereon to travel down the upper sloping surface of the carrier plate 45 and as soon as the roller passes over the apex and engages the-under sloping surface snaps the carrier plate 45 about its pivot to open the ignition switch, as shown in Figure 3.

The period between the closingof the motor circuit and the opening of the ignition switch is predetermined by adjusting the length of the travel of the actuating roller over the upper sloping surface of-the carrier plate 45.

-A means for adjusting the length of the travel is shown in Figures 5 and 6, which includes a hooked latch member 58 mounted to extend upward from the outer side of the right angular extension 44 of the ignition switch carrier plate 45 with the hook of the latch adapted to contact with an adjustable abutment- 59 mounted in a right ang lar struck up portion 60cof the front plate 13 which will limit the downward movement of the carrier plate 45. By raising the abutment 59 the roller is caused to approach the apex and the nearer the actuating roller is to the apex of the sloping surfaces of the carrier. plate the less the movement required to snap the ignition switch to the open position and vice versa. As shown in 'Figure l, the adjustment is such that the actuating roller is nearly at its upper limit of travel and mustmove over the sloping surface before snapping theignition switch to the open posltion. The movement of'the ignition carrier plate 45 about its pivQin the opposite direction is limited by upper surface of the angular extension 44, which passes under the, front plate 13, engaging with the edge 13' thereof.

it is necessary that the hot wire W of the ignition device be heated sutliciently'to become incandescent bythe time the motor switch is closed to cause the motor to supply fuel to the burner, and this period between the closing of the ignition circuit and the time the motor switch closes is referred to as the pro-heating period. This pro-heating period may be predetermined b the proper adjustment of the length of t e actuating link 54, by anyd'esired means, such as the sliding adjustment 54 shown. The greater the travel of the free end ofthe thermal member T before the actuating link 54 operates the actuating member 52 and arm 63 to allow the motor switch to close, the longer the preheating period.

The above is the normal'cycle of operation of the parts when the room thermostat R closes the line circuit to the control. Under normal conditions the motor switch is closed during a predetermined time before the igni: tion switch is automatically opened.

As heretofore stated, the motor switch is mounted on the upper side of a pivotally mounted carrier plate 48, and the portion of this plate. below the pivot 49 is extended in adjacent the rear of the base plate 12 is provided with a fixed pin 64 passing through The actuating member 52 is an opening 65 provided therefore in the base 3 plate 12 the inner end ofwhich is pivotally connected to one end of a lifting lever 66 which lever is mounted intermediate its length upon a pivot 67 mounted adjacent the left edge of the base plate 12. The lower portion of the yoke 9 is provided with a vertical slot 68 in line with the pin 64 adapted to receive and in the cold position engage at its bottom a pin 69, passing throu h an aperture 70 provided therefore in the ase plate 12, carried on a coacting lifting lever 71. This coacting lifting lever 7 l is in the shape of a bell crank lever only it is pivoted intermediate the length of the arm opposite that carrying the pin 69 upon a pivot pin '72 67 of the lifting lever 66. The apexof the lever 71 is above its pivot 72 and carries a stud 73 which in the cold position extends over and above the curved extension to the abutment 61 of the motor switch carrier plate 4-8 and prevents the closing thereof.

The weight of the primary coil is suflicient when in deenergized position upon the feet 11' to hold the yoke 9 with its feet in engagementwith the stationary secondary coil 5, as 1 shown in Figure 1. The portions of the lifting lever 66 and coactin lifting lever 71 extend unequally to the le%t of their respective pivots 67 and'72 while the distance from these pivots to the respective pins 64 and 69 upon the inner ends of the respective levers is the same. As shown in Figure l, the upper lift-' ing lever 66 extends a greatep distance to the left than the lower cooperatlng lifting lever 71 and the left end portions are connected by a coil spring 74 its upper end being at a greater distance from pivot 67 than the distance of its lower end from pivot 72 so that the tension of the spring will cause an n ward movement to be imparted through pin 64 to the yoke 9 when the primary coil 6 is energized and floats above the stationary secondary coil 5. The upward movement of the yoke 9 is limited by its fixed pin 64 enga g tllie upper side of the aperture 65 in the li ai se ate 12. p The normal voltage of the commercial line circuit is sufiicient to cause the tprimary coil 6 to float above the feet 11 0 the yoke 9 as the yoke9 assumes its upper position in which position it is held during normal 0 eration before the coil 6 is deenergized. 'Fo absorb the shock of the falling of the coil 6 when deenergized, upon t e feet 11, and thereby prevent any undue strains 11 on any of the parts of the control mechamsm, the slot 68 is provided in the yoke 9 to receive the pin 69 and allow a .reci rocation of the yoke 9 thereover against t e tension of the spring 7 4.

' The u ward movement of the yoke 9 changes t e relative positions of both lifting lever 66 and coacting lifting lever 71 so that the stud 73 upon lever 71 is moved upward away from the pro'ection of the carrier plate 48. The weight 0 motor switch being supported to the right of the pivot 49 of its carrier plate woul normally rotate the motor switch to closed position but the abutment 61 of the carrier plate enga es the arm 63 of the actuating member 52 w 'ch remains in the position shown in Figure 1 until the heating of the thermal member T causes it to move about its pivot which raises the end of the actuating arm 63 contacted by the abutment 61, and as this movement takes place the motorswitchgraduallyapproachesand finallyassumes the closed position shown in Fi It is therefore seen that the closin deenergizes t e floatin coil*6 and its weight would depress the .yo e 9 causing stud 73 upon lever 71 to en age and rotate the motor switch carrier p ate 48 to open the motor switch. To prevent such action provision'is made to lock the motor switch when" once closed and hold it closed 'duringthe normal operation of the burning mechanism,

as hereinafter described.

. Again referring to the wiring diagram on Fi re 3, it is seen that when the motor SWltCh is closed, the incomin current at binding post 18 branches an part passes gure 3. of the room thermostat R first energizes t e igni-- through lead 19, closed motor switch 15,- lead 32, burner motor M, binding post- 35, lead 36 and binding 0st 30 to return lead 31 to the commercial 'ne, and at the same time through lead 37 energizes the electrically operated valve 0 in the fuel supply to cause it to open.

As the ignition circuit is closed when the motor M starts and remains closed a redetermined time thereafter, sufficient time is allowed to ignite the fuel and the flame therefrom to close the stack switch S, whereupon a portion of the incoming current passes from binding post 23 by the way of lead 25, bindin post 26,- lead 27, closed stack switch S, bin ing post 28, leads, 29, through windings'of electro-magnet E to binding post 30 and re turn lead 31 to the commercial line.

The electro-magnet E is provided with a pivoted armature 7 5 pivoted at having an extension 76 mounting at its free end an actuating stud 77 which whenthe armature is closed, by the energizing of the magnet E, is caused to engage the under side of a weighted arm 78 of a bell crank locking lever pivoted at its a ex on the ivot pin 79 mounted on the base p ate 12 and rotate the same about its pivot. The other arm 80 of the crank lever is provided adjacent its free end with a depression on the side adjacent the motor switch carrier plate to form a latch 81 so that when the motor switch is closed and the ma et E is energized the projecting catch 62 on the motor switch carrier late is engaged within the depression and he (1 by the latch 81 from counter revolution to open position.

After the parts 62 and 81 engage and lock the motor switch in closed position the igni-' tion switch is opened and as long as the magnet E remains energized it will hold the parts locked, as 'above described, which will through stud 73 engaging the upper side of the immovable carrier plate 48 of the motor switch and tension of lifting spring 74 maintain the yoke 9 in its uppermost position supporting the primary coil 6 upon its feet 11, as shown in Figure 3.-

' When the ignition circuit is opened, the

thermal member T gradually cools, the actuating member 52 having opened the ignition switch is locked from counter revolution by the engagement of the actuating arm 63 with theabutment 61 ofthe locked motor switch carrier plate'48, and actuating link 54 is allowed to move to the left as the member T cools by the slot 55 passing over the pin 56 on the lockedactuating member 52, and place the spring 57 under tension.

The above description of the movement of the parts from cold to normal running position is undernormal conditions, that is the fuel is promptly supplied and ignited and the switch responsive to the presence of the flame closes normally while the boiler control remainsclosed and the current from the commercial line is uninterrupted, J

It is to be noted here, that should the/fuel fail to ignite during the period the ignition circuit is energized the stack switch S, which is normally open, will not close the circuit through the holding magnet E, so that the latch 81 will not engage the catch 62 of the motor switch carrier plate 48. Therefore, when the primary coil is deenergized by the normal operation of the thermal member T, actuating link 54 and actuating member 52 opening the ignition switch 14, the weight of the coil upon the yoke 9 will depress the yoke which through engagement of the stud 73 with carrier plate 48 of themotor switch 15 will tilt the motor switch to open the motor circuit. Unless the actuating arm 63 of the actuating member 52 is prevented from following the downwardly moving abutment 61 as the carrier plate 48 tilts, the ignition switch 14 will be returned to closed ition and the operation repeated indefinite y. To prevent this, the actuating member 52 is provided with a shoulder 82 adapted to'wipe over the top of the arm 80 of the locking lever which, since the holding magnet E has remained de- 1 energized, remains in its normal position, as

shown in Figure 4, as the actuating member during its normal operation opens the ignition switch, so that the end of the arm 80 engages the shoulder 82 as the thermal member T cools and prevents counter rotation of the actuating member 52 and when the yoke 9 drops and opens the-motor switch 15, the ignition switch 14 is locked in open position and the control must be manually reset before the burner mechanism can again be made to perate. p

The manual reset device is shown in side elevation in- Figure 2 and in dot and dash lines in Figure '4. It includes a knurled knob 83 mounted on a shaft passing through the .cover plate '4'- which mounts on the interior of the cover-plate an inn 84 carrying on its free end a pin 85 which upon rotation oi the knob 83 will contact the armature '1 5 of the holding magnet E to cause the stud 7 7 to en gage the arm 78 and rotate the locking lever to move the end of the arm 80 out of engage- 4 ment with the shoulder 82 to release the actn= the room thermostat R and the arts are in ating member 52 to complete its normai operation and close the ignition switch 14:, and all the parts will be in the cold position, as shown in Eigure 1.-

-Whei i="-"the burner mechanismhas heen caused to operate normally by the closing oi the running position shown in ignre 3 and the desired temperature has been obtained, the room thermostat'R will open the circuit therethrough, and therefore the current which has been passing through the boiler control C, stack switch S and olding mag net E ceases The breaking of the circuit through the holding magnet E releases the locking lever so that latch 81 disengages catch 62 allowing the weight of the coil 6 and yoke 9 to tilt the motor switch-15 to open position. To allow the arm 63 of the actuatin member 52 to follow the abutment 61 of t e carrier plate 48 as its tilts without engaging the shoulder 82 on the actuatin member with the top of arm 80, as occurs w 11 initial ignition fails, a restart plate 86 is provided, pivoted at one end on a pin 87 mounted on the upper right corner of the base plate 12, and so formed as to normally rest upon the pivot 53 of the actuating member 52, when theFparts are in the running position shown in i gure 3, with a portion extending beyond the shoulder 82 to be engaged by a pin 88, adjacent the end of the ating member to rotate with the arm 63 there of following the tilting abutment 61 and causing the actuating roller to pass over the apex of the nose of the ignition switch carrier 45 to close the ignition switch and at the same time the upward movement im arted' to the pivoted end of the actuating ever 50 engages a stud 89 on the re-start plate 86 lifting the tree end thereof to clear the pin 88, as shown in Figure 1. The ignition switch being returned to closed position and the motor switch open, the parts are in position to re-start the burner mechanism upon the closing of the room thermostat R.

In case the burner flame fails for any reawn after initial ignition and the parts of the control have assumed'the normal run ning position shown in Fi ure 3, the stack switch S will open brea ing the circuit through the holding magnet 1E, whereupon the parts wili assume the cold position the same as if the room thermostat had opened,

However, the room thermostat R heing closed as soon as the ignition switch is bronsht closed position again the thermal menu er '1? will heat and the motor switch released to close by the upward moving yoke 9, and the ire-start plate 86 being lifted when the nctuating member 52 closed the ignition switch the second time allowing the end of the 80, while the holding magnet E is de-energized to enter under the shoulder 82 of the actuatin member 52 asthe ignition switch is opened t e second time and the parts wili assume the position shown in Figure 4 and require amanual reset before the burner mech anism can be again operated, in the same mannerasifi ignition has initially failed.

A safety control for a liquid fuel burner should provide means upon an interruption of the line current to shut down the. burner motor a sufficient time to allow the unburned vapors of the fuel to leave the combustion chamber before again discharging the fuel thereinto. This invention .contemplates to compensate for a current interruption in the following manner:

A current interruption occurring while the room thermostat is open does not affect the control except that should the thermostat close during the interruption the burner mechanism could not be started until the current was resumed and then the control would function normally to start the burner.

In case the current interruption occurred with the room thermostat R closed and after the motor switch had been normally closed but before the stack switch S closes, the holding magnet E would not be energized to lock the motor switch carrier 48 in the closed position, as shown in full lines in Figure 7 so that as soon as the current ceased the primary coil 6 would be deenergized, drop upon the feet 11 and depress the yoke 9 immediately tilting the motor switch carrier 48 through pin 73 to open the motor switch, as shown in dot-and-dash lines in Figure 7. The failure of the current deenergizes the ignition circuit and therefore the thermal member T would cool and cause the shoulder 82 to engage the upper end of arm 80 as in case of an initial failure of ignition, as

- shown in Figure 4, and necessitate a manual reset. This is not desirable and to prevent. this locking of the parts a pawl 90 is pivotally mounted upon the free end of a pawl carrying continuation 91 of the cooperating lever 71, as shown in Figure 7 The pawl 90 approximates a square in shape and is pivoted intermediate and adjacent its right edge with the left edge cut away to form a stop 92 at each left corner adapted to engage a projection of the pin 69 carried on the cooperating lever 71 on that side to limit the movement of the pawl 96 about its pivot.

' The pawl 90 is also provided with a stud 93 at its upper right corner adapted under certain conditions to engage the arm 80 and at its lower right corner with a projection or r nose 94. A counter weight to normally tilt the ignition switch into closed position, if spring 51 were released, in the form of a plate 95 is attached to the carrier plate and mounts a stud 96 which lies in the path of travel of the nose 94' of the pawl 90.

When the yoke 9 drops from the full line position to the dot and dash position shown in Figure 7 it not only tilts the motor switch carrier 48 through pin 73 to open the motor switch by the downward movement imparted to the cooperating lever 1 but also carries the pawl 90 to the dot and dash line position. At the start of this movement the ignition till switch is in closed position with the nose 94 of the pawl above the. stud 96. The downward movement of. the prolongation of the Y cooperating lever- 71- causes the nose ,94 to engage the-stud :96 whereby 'the'stud 93 of the pawl 90 engages the arm 80 moving the end of the arm: 80' out got the path'of the shoulder 82 of the actuating member 52 and then ride .over'the surface ofthe arm 80 as the nose 94 swings the'carrier plate 45 about its pivot until the. actuating. roller of the actuating lever passes over the apex of the nose of the carrierplate and snaps. it into the open position of the, ignition switch, as shown in dot'a-nddash lines in Figure 7.

Therefore as the. thermal member T cools,

the parts all assume the cold position shown .in Figure 1.

" As soon as the current is interrupted the" circuit through the primary coil 6 is broken and it innnediatelydrops and the rmotor switch and ignitionswitchjes are immediate ly both tilted into' open position-and the. thermal element must cool'and return the ignition 'switchto closedipositionbefore any resumption of current can again operate the control to start the burnermechanism.

In case the current interruption occurs when the thermostat R- has closed and the stack switch closed, asnormally, but before the ignition switch has been moved to open position, the parts will -be in the position .shown in full; lines in FigUr Sand-the dropping of the coil 6 will..at the-. same.-time t e holding magnet-E is deenergi zed, trip the ignition carrier plate-45 to open the ignition switch \by the. movement of the pawl and the reset plate 86-haying fallenbelow stud 88 will hold the end of arm 80 out of engagement with the shoulder 82 ofthe actuating member 52, as shown in dot and dash lines,

whereby as the thermal member T cools the actuating member 52 will normally snap the ignition switch into closed-position so that the parts will be-returnedlto the normal cold position andupon resumption of current at time after the interruption, the control normally act to start. the burner mechanism. r,

a In case there is acurrent interruptionwhile the burner is normally operating and immediately resumes before the stack switch opens or in case the room thorm'ostatR is manually operated to first. open theeircuit and then closeit, the parts being inthe normal rum ning'position as shown in. Figure3, the. ignition switch. is open and the motor switch is locked inclosed' position by the holding magnet the momentary interruption will momentarily disengage the holding magnet E and as the armature thereby is momentarily freed, the weight of thecoilfi ,will causethe yoke to drop as the latch. 81 momentarily frees the catch 62 of themotor switch carrier 48 so that the yoke 9 tilts the carrier 48 to open switch into closed position and the immediate reenergizing of the holding magnet E causes the latch 81 to engage under the catch 62, as shown in Figure 9, and lock it in that position until the stack switch coolsand deenergizes the holding magnet E to allow the arm 80 to resume its normal position and thereby release the motor switch carrier 48 and allow it to normally close the motor switch when the actuating arm 63 has been removed from contact with abutment 61. The closing of the ignition switch causes the coil 6 to float and the yoke 9 to ascend and in so doing the pawl 90 being pivoted in ascending wipes its nose 94 over the stud 96. The control then continues its normal cycle and opens the ignition switch and the parts again as sume the running position. I

In each of the three instances of current interruption above described the control is caused to recycle upon current resumption and start the burner mechanism to recycle upon current resumption and start the burner mechanism to operate normally without a manual reset of the control. Also in each in stance there is first a shut down of the burner as the motor switch is opened and the time consumed from the interruption and shut downto the end of the rec cling operation of the control is suf'n'cient to fi'ee the combustion chamber of unburned fuel vapors so that there is no danger when the fuel is again supplied.

What claim is: 1. A control for an electrically operated .fluid fuel burner mechanism including a constant current transformer having a coil that will float when the transformer is energized, and means controlled by the movement of the floating transformer coil to permit the operation of the burner mechanism.

2. A control for an electrically operated fluid fuel burner mechanism including a constant current transformer having a coil that will float when the transformer is energized,

and means controlled by t e movement of the floating transformer coil to rmit and stop the operation of the burner mechanism.

3. Acontrol'for an electrically operated fluid fuel burner mechanism having a burner fluid fuel burner mechanism having a burner motor including a constant current transformer, a switch in the motor circuit normal- 1y open, and means operable upon energizetion of the transformer to close said switch to operate the burner mechanism, thereafter breaking the circuit through the transformer, and means responsive to combustion to maintain the circuit throu h the motor, said first means including a switch in the transformer circuit normally closed and operable to automatically open at predetermined time after the transformer has been energized.

5. A control for an electrically operated fluid fuel burner mechanism having a burner motor including a constant current transformer, a switch in the motor circuit normally open, and means operable upon energization of the transformer to close said switch to operate the burner mechanism, thereafter break the circuit through the transformer,

- and combustion responsive means to maintain the circuit through the motor, said first means including a switch in the transformer circuit normally closed and operable to automatically open a predetermined time after the transformer has been energized, and further including a thermal member in the transformer circuit actuated by the passage of the current therethrough to cooperate with and open the switch in the transformer circuit.

6. A control for an electrically operated fluid fuel burner mechanism having a burner motor including a constant current transformer, a switch in the motor circuit normally open, means operable upon energization of the transformer to close said switch to operate the burner mechanism, thereafter breaking the circuit through the transformor and combustion responsive means to maintain the circuit through the motor, said first means including a switch in the transformer circuit normally closed and operable to automatically open a predetermined time after the transformer has been energized, and further including athermal member in the transformer circuit actuated by the passage of the current therethrough to cooperate with and open the switch in the transformer circuit.

v 7. A control for an electrically operated fluid fuel burner mechanism including a constant current transformer having a coil that A will float when the transformer is energized, and means controlled by the floating of the transformer coil to permit the operation of the burnermechanism, includinga normally open motor switch; and means operable upon energization of the transformer and upon the floating of the coil to close the motor switch and lock said switch closed during normal operation of the burner.

8. A control for an' electrically operated fluid fuel burner mechanism including a con- 'stant current transformer havin a coil that will float when the transformer is energized, and means controlled by the floating of the transformer coil to permit the operation of the burner mechanism, including e1 normally burner flame and a holding magnet in ciropen motor switch; and means op able upon cuit with the source of electricity adapted energization of the transformer and the floatwhen said latter switch is closed to energize ing of the coil to close the motor switch and the magnet to lock the motor switch. 5 look said switch closed and support the said 12. A control for an electrically operated 70 coil during normal operation of the burner. .fluid fuel burner mechanism having a burner 9. A control for an electrically operated motor including a constant-current transfluid fuel burner mechanism including a conformer, a switch in the motor circuit normalstant current transformer having a coil thit ly open means operable upon energization 1 will float when the transformer is energized, of the transformer toclose the motor cir- 75 and means controlled by the floating of the cuit to operate the burner mechanism, theref/ transformer coil topermit the operation of after break the circuit-through the transthe burner mechanism, including a normally former and maintain the circuit through the open motor switch, and means operable upon motor, said means including a switch in the energization of the transformer and the floattransformer circuit normally closed a therso ing of the coil to close the motor switch and mal member in the transformer circuit actulook said switch closed and support the said ated by the passage of the current therecoil, and means actuated upon cessation of through to open the switch in the transformer operation of the burner by the weight of the circuit after a predetermined time, and supported coil to open the motor switch. means operable during the normal operation 10. A control for an electrically operated of the burner mechanism to lock the motor fluid fuel burner mechanism having a burner switch in closed position during the conmotor including a constant current transtinued normal operation of said mechanism, former having a movable coil, a switch in includinganormally open switch operable to the motor circuit normally open, a switch in close upon ignition of the fuel, a holding at the transformer circuit normally closed, and magnet in series, therewith, and means actumeans operable upon energization of the ated by energizing the magnet to lock the transformer to close the motor switch to opermotor switch, said means releasing said ate theburner mechanism, thereafter break motor switch upon deenergization of said the circuit through the transformer and magnet. 9t maintain the circuit through the motor, in- 13. A control for an electrically operated eluding a spring pressed merr )er depressed fluid fuel burner mechanism having a burner by the weight of the movable coil of the motor including a constant current transtransformer when the circuit to the control is former having a floatable coil, an electrical open and operating upon closing the circuit ignition device connected in circuit with one at and floating of said coil to release the motor coil thereof, a normally closed ignition switch switch for closing motion and further inconnected in circuit with the other coil thereeluding means to close the motor switch and of, a normally open switch connected in the open said transformer switch and means to motor circuit, a holding magnet, a normally look said member to support the said coil in open combustion switch adapted to close upon 195 its floating position upon the opening of the ignition of the fuel in circuit with said magtransformer switch, said member upon the net and source of electricity, means for openbreaking of the control circuit actuated by mg and closing the ignition and motor the weight of the supported coil to actuate switches including: a movable member northe motor switch to open. mally held from movement by the weight of 1,1

11. A control for an electrically operated the deenergized floatable coil Of the transfluid fuel burner mechanism having a burner former, means upon said member for movmotor including a constant current transmg {1nd holdlng the motor switch open in asformer, a switch in the motor circuit normallng the deenergized position, thermal 1y open, means operable upon energization of means the ignition circuit for actuating ".11., the transformer to close the motor switch to e gn1 1 n swltch and releasing said motor operate the burner mechanism, thereafter SWItQh o open, means actuated upon closing b k th ir it th ough th tr f the circuit to the control to impart movement and maintain the circuit through the motor; to Bald m v ahle member as the energized i id means i l din a wit h i th t transformer coil floats thereabove, to release 1'4. fo r i it ll l d a th l the motor switch to open, said thermal memmember in the transformer circuit actuated h a predetermined time thereafter p by the passage of the current therethrough to g to pen the ignition switch and allow open th it h in th tran for r i uit therebefore the motor switch to close; said after a predetermined. time, and means opercombustion switch upon ignition of the burn- 1 able during the normal operation of the er flame energizing the holding magnet to burner mechanism to lock the motor switch lock the motor switch in open position and in closed position during the continued norhold the moveable member in its mov d posimal operation of said mechanism, including a tion supporting the weight of the (leenergized switch responsive to the presence of the floating coil of the transformer.

14. A control for an electrically operated fluid fuel burner mechanism havin a burner motor including a constant cur ent transformer having an immovable secondary and a movable primary coil, an electric ignition device connected in circuit with the immovouit, a holding magnet, a combustion switch connected in circuit with the moveable primary coil thereof, a switch in the motor circuit, a holding magnet, a combustion switch responsive to the presence of the burner flame in circuit with the holding magnet and source of electricity, switch 0 erating mechanism for the ignition switc switch operating mechanism for the motor switch, a springpressed fimliei' havifig fconiiection with the motor switch operating mechanism and connected to be normally depressed by the weight of the dead primary coil to hold the motor switch open, a thermal member in the i ition circuit having an operative connection to the ignition switchmechanism, acting when cold to close the ignition switch and also connected to hold the motor switch open, whereby upon closing the circuit to the control, the transformer is energized, the floating of the primary coil releases the springpressed member to release the motor switch, the secondary ignition circuit causes the ignition device to o erate and begins to heat the thermal mem er heating movement of which acts to operate the switch mechanisms to first release and allow the motor switch to close and then open the i ition switch,

the presence of the flame of t e ignited fuel causing said combustion switch to close the circuit to the holding magnet, and means actuated by the energizing of the holding magnet to engage and lock the motor switch mechanism with the motor switch closed before the ignition switch opens and thereby lock the spring-pressed member to support the weight of the floating coil as the ignition switch is opened and prevent. the cooling movement of the thermal member closing the ignition switch.

15. A control for an electrically operated fluid fuel burner mechanism having a burner motor including a constant current transformer having animmovable secondary and a movable primary coil, an electric ignition device connected in circuit with the immovable secondary coil thereof, an ignition switch connected in circuit with the moveable primary coil thereof, a switch in the motor cir cuit, a holding magnet, a combustion switch responsive to the presence of the burner flame in circuit with the holding magnet and source of electricity, switch operating mechanism for the ignition switch, switch operating mechanism .for the motor switch, a springpressed memberhaving a connection with the motor switch operatin mechanism and connected tobe normallyepressed by the weight of the dead primary coil to hold the motor switch open, a thermal member in the ignition circuit having an operative connection to the ignition switch mechanism, vacting whem cold to close the ignition switch and also connected to hold the motor switch open,

whereby upon closing the circuit to the control, the transformer is energized, the coating of the primary coil releases the springpressed member to release the motor switch, the secondary ignition circuit causes the ignition device to operate and begins to heat the thermal member, heating movement of which acts to operate the switch mechanisms to first release and allow the motor switch to close and then 0 en theignition switch, the presence of the ame of the ignitedifuel causing said combustion switch to close the circuit to the holding magnet, and means actuated by the energizing of the holding magnet to engage and lock the motor switch mechanism with the motor switch closed before the ignition switch opens and thereby lock the spring-pressed member to support the weight of the floating coil as the ignition switch is opened and prevent the cooling movement of the thermal member closing the ignition switch, and upon thereafter opening the circuit to the control, the deenergizing of the holding magnet releases the motor switch, whereupon the weight of the dead coil depresses the spring-pressed member to open and hold the motor switch open, and allows the ignition switch mechanism to close the ignition switch.

16. A control for an electrically'operated fluid fuel burner mechanism having a burner motor including a constant current transformer having an immovable secondary and a movable primary coil, an electric ignition device connected in circuit with the immoveable secondary coil thereof, an ignition switch connected in circuit with the moveable primary coil thereof, a switch in the motor circuit, a holding magnet, a combustion switch responsive to the presence of the burner flame in circuit with the holding magnet and source of electricity, switch operating mechanism for the ignition switch, switch operating mechanism for the motor switch, a spring-pressed member having a connection with the motor switch operating mechanism and connected to be normally de-. pressed by the weight of the dead primary coil to hold the motor switch open, a therthe heating movement of which acts to opswitch mechanism with the motor switch erate the switch mechanisms to first release closed before the ignition switch opens and and allow the motor switch to close and then thereby lock the spring-pressed member to open the ignition switch, the presence of the support the weight of the floating coil as the flame of the ignitedfuel causes said combusignition switch is opened and prevent the tion switch to close the circuit to the holding cooling' movement of the thermal member magnet, and means actuated by the energizclosing the ignition switch, and upon intering of the holding magnet to engage and lock ruption of current to the control after the the motor switch mechanism with the motor motor switch is closed and the holding mag- 1 switch closed before the ignition switch opens net energized but before the ignition switch 75 and thereby lock the spring-pressed member is opened, the holding magnet and floating to support the weight of the floating coil coil are both deenergized whereby the holdas the ignition switch is opened and prevent ing magnet actuated means releases the motor h w the cow novement of the thermal memswitch mechanism and the weight of the dead ber closing the ignition swi'tEhTsa idmeans coildepresses the spring-pressed member to Q0 upon failure of energization of the holding open and holdthe motor switch open and actumagnet being operative to engage the igniates additional means provided for operattion switch mechanism and prevent the closing the ignition switch mechanism to open ing of the ignition switch, whereby the the ignition switch and then allow the therweight of the dead coil upon the opening of mal member to close the ignition switch, 5 the ignition switch depresses the springwhereupon the resumption of current will pressed member and opens and hold the mo again actuate the control. tor switch open until said holding magnet 18. A control for an electrically operated actuating means is manually operated to refluid fuel burner mechanism having a burner lease the ignition switch mechanism to again motor including a constant current transclose the ignition switch. former having an immovable secondary and a 17. A control for an electrically operated movable primary coil, an electric ignition defluid fuel burner mechanism having a burner Vice connected in circuit with the immoveamotor including a constant current vtransble secondary coil thereof, an ignition switch 30 former having an immovable secondary and connected in circuit with the moveable pri- '95 a movable primary coil, an electric ignition mary coil thereof, a switch in the motor cir device connected in circuit with the immovecuit, a holding magnet, a combustion switch able secondary coil thereof, an ignition responsive to the presence of the burner flame v switch connected in circuit with the moveable in circuit with the holding magnet and primary coil thereof, a switch in the motor source of electricity, switch operating mech- 10o circuit, a holding magnet, a combustion anism for the ignition switch, switch operatswitch responsive to the presence of the burning mechanism for the motor switch, a springer flame in circuit with the holding magnet pressed member having a connection with and source of electricity, switch operating the motor switch operating mechanism and mechanism for the ignition switch, switch Connected to be normally depressed by the operating mechanism for the motor switch, Weight of the dead primary coil to hold the a spring-pressed member having a connection motor switch open, a thermal member in the with the motor switch operating mechanism ignition circuit having an operative conncc and connected to be normally depressed by tion to the switch mechanisms acting when the weight of the dead primary coil to hold cold to close the ignition switch and also hold the motor switch open, a thermal member in the motor switch open, whereby upon closing the ignition circuit having an operative conthe circuit to the control, the transformer is nection to the ignition switch mechanism, nergized, the floating of the primary coil actin when ld to clo e th i niti wit h releases the spring-pressed member to release 0 and also connected to hold the motor swit h the motor switch, the secondary ignition CiI' open, whereby upon closing the circuit t cult causes the ignition device to operate and the control, the transformer is energized, the h 'g to heat h h rmal ember the heatfl ti f th i il releases th lug movementof which acts to operate the spring pmsscd member t release th motor switch mechanisms to first release and allow 55 switch, the secondary ignition circuit causes i fl Switch to @1059 and then p the the ignition device to operate and begins to Q fi lt-ch, the presence of the flame of heat the thermal -m th h t movethe ignited fuel causes said combustion switch ment of which acts to operate the switch t0 01058 e rClH to the holding magnet,

, mechanisms to first release and allow the and means actuated by the energizing of the motor switch to close and then open the igholding magnet to engage and lock the mo 1 nition switch, the presence of the flame of tor switch mechanismwith the motor switch the ignited fuel causes said combustion switch closed before the ignition switch opens and to close the circuit tothe holding magnet, and thereby lock the spring-pressed member to means actuated by the energizing of the holdsupport the weight of the floating coil as the ing magnet to engage and lock the motor ignition switch is opened and prevent the cooling movement of the thermal member closing the ignition switch, and. upon a moholding magnet and floating coil occurs and causes a release of the motor switch and the weight of the dead coil to depress the spring pressed member to open the motor switch and allow the ignition switch mechanism to close the ignition switch, and the immediate.

re-energizationof the holding magnet actuates the motorswitch locking mechanism to lock the motor switch in open position, whereupon combustion ceases and thereafter the holding ma et is deenergized to release the motor switc andthe control re-cycles in going through the'movements of a normal startt IRA E. MCCABE.

Patent No. l, 881, 321.

lRA E. McCABE.

CERTlFlCATE 0F. CORRECTION.

October 4, 1932..

lt is hereby certified that error appears in'the printed specification of the;

above numbered patent requiring correction as follows:

Page ll,t.l ine 7', claim 14, Strikeout the "syllable and-words "cuit, a; holding .-magnet, a combustion" and insert instead thesyl'lable' and words "able secondary coil thereof, an ignition",

and lines 72 and73. claim 15, for "coating" read "floating"; and that the-said Letters Patent should be read with these corrections therein that the same may conform to the record oi the case in the Patent Office.

Signed and sealed this 28th day of February, A. D. 1933'.

(S eal) a Mr]. re, Acting connnissmbr of Patents. 

